Incompatible browser

Internet Explorer versions 7 and older have known compatibility and security issues with modern
web standards which affect next generation Web 2.0 websites. In our attempt to deliver a superior
experience, we no longer support Internet Explorer versions 7 and older.

Please upgrade to the latest
version of Internet Explorer, Firefox, Safari or Chrome.

For projects in Radon Zone 1, if there is a 3rd party testing to show that there is not a Radon issue in the area - can the prerequisite be skipped?

Inquiry

For projects in Radon Zone 1, if there is a 3rd party testing to show that there is not a Radon issue in the area - can the prerequisite be skipped?

Ruling

Radon cannot be tested for prior to construction, so homes in EPA Zone 1 must have radon-resistant construction. For homes that overlook this prerequisite, project-specific CIRs may be submitted and post-construction radon testing may be allowed as an alternative.
Updated 10/1/13 for rating system applicability.

Does the vent pipe need to go all the way to the roof? Is it good enough to have it capped tightly and labeled?

The project plans to use the following strategy for radon mitigation:

The...

Inquiry

Does the vent pipe need to go all the way to the roof? Is it good enough to have it capped tightly and labeled?

The project plans to use the following strategy for radon mitigation:

The sub slab meets the requirements of radon resistant construction, including a 6mm plastic lining, a gas permeable layer and a sealed foundation. The vent pipe is capped tightly and labeled, but it does not go all the way through the roof. We could have taken the pipe through the roof if needed but didn't want to put more holes than needed in the roof, especially with a 10 kW solar up and under-roof solar thermal to deal with. I don't think a normal builder would want to do this until tests showed that radon was a problem either. We had Mid-Atlantic Associates, a third-party environmental consultant, perform indoor air quality samples to test for radon, among other pollutants. Tests showed that radon were well below levels of concern. These are attached.

Ruling

Radon-resistant new construction requires the sub-slab pipe to be vented to the outside, either through the side wall or roof. It is not acceptable to cap the pipe inside the home.
Updated 10/1/13 for rating system applicability.

Is RRNC required for a home that is built on concrete piers with the enclosed envelope of the house a good 2 feet above the ground. The space between the house and the ground is completely open and c...

Inquiry

Is RRNC required for a home that is built on concrete piers with the enclosed envelope of the house a good 2 feet above the ground. The space between the house and the ground is completely open and continuously vented to outside air. All penetrations of the floor are sealed to the outside (SIPS panels used).

Ruling

If the home is raised above the ground by 2 feet and the space is completely open to the outside such that there is continuous air flow, then radon resistant new construction is not needed. EQ 9.1 is waived, and if the home is in EPA Radon Zone 2, the home can earn credit for EQ 9.2.

For an active radon mitigation system, is there any reason the inline fan couldn't be located in the basement mechanical room as opposed to the attic, if it was necessary? I will check the EPA web si...

Inquiry

For an active radon mitigation system, is there any reason the inline fan couldn't be located in the basement mechanical room as opposed to the attic, if it was necessary? I will check the EPA web site but thought you may have come across this before.

Ruling

To be clear, a fan is not required as part of EQ 9.1 - it only refers to passive radon resistant construction techniques. Applicable Internationally.

Generally, it is best practice to have the fan at the edge of the envelope to prevent pressurizing the exhaust pipe, which can create a greater risk of radon entry into the home in the event of a system leak. Having the fan outside the envelope can increase the risk of failures, especially in cold climates. In every case, the fan should be in a place that is accessible, in case of failures. Once a fan is installed, be sure to seal the exhaust pipe and test for leaks. Refer to the EPA site and the EEBA Guides for more information.
Updated 10/1/13 for rating system applicability.

Can this prerequisite be satisfied with mechanical ventilation in the basement or crawl space?

Inquiry

Can this prerequisite be satisfied with mechanical ventilation in the basement or crawl space?

Ruling

No. A typical exhaust only ventilation system does not meet the requrements for Radon Resistant New Construction (RRNC). In fact, exhaust only mechanical ventilation may increase radon concentrations indoors. RRNC requires a capilary break beneath the slab, a vent stack from below the slab to above the roof line, and provision for installation of a radon-rated exhaust fan (if needed). Applicable Internationally.

We welcome and value the opinions of our green building community. We are collecting feedback on LEED v4 during the 5th open commenting period. At this time, each USGBC site user may comment on the open credits.

Please note:

Only one comment per individual is allowed

Once the comment is submitted, it cannot be edited

Users may comment within the credit library, or on LEEDuser.com (but only one comment will be accepted for both sites)

Users must note if they want their comment to be private (and not viewable by the USGBC community)